The invention relates to a device for selecting pile yarns in gripper Axminster weaving machines, more specifically in carpet weaving machines of the gripper Axminster type. With such weaving machines the pile yarns of different colors are placed in a number of elongated pile yarn carriers axially movable according to their length. Each pile yarn carrier is provided for positioning a number of pile yarn ends at mutual distance according to the length of the pile yarn carrier. Each pile yarn carrier is provided with a number of pins at mutual distance according to the length of the pile yarn carrier corresponding to the number of colors. Each pile yarn carrier is under control of a control device according to a pattern, through the pin for the selected pile yarn which works together with a sliding mechanism, axially movable according to its length, in order to present the pile yarn end of the selected pile yarn to an associated gripper jaw for taking up a pile yarn end.
In such carpet weaving machines the pile yarns are held in pile yarn carriers which protrude in a horizontally, obliquely or vertically disposed direction. The pile yarn ends protrude out of the pile yarn carriers sufficiently on one side in order to be taken along by gripper jaws. The gripper jaws are rotatably disposed in order to grip the protruding pile yarn ends in an upwardly rotating movement and in order to bring these downward, so that they can be woven into the backing fabric of the carpet.
Patent publication GB 1 150 822 describes a known jacquard device for selecting pile yarns with a different color in gripper Axminster weaving machines. This jacquard device provides horizontally disposed pile yarn carriers, which are moved in a horizontal direction, so that the pile yarn with the selected color is brought to the pick line of the gripper jaws. With these weaving machines the pile yarns extend in an almost vertical direction. In order that the gripper jaws would be able to take up a selected color according to pattern, the various pile yarns are placed next to each other in one and the same pile yarn carrier. This arrangement is favorable for achieving a high weaving speed.
The selected color according to the pattern to be woven is therefore obtained by a sliding of the pile yarn carriers performed by a jacquard device, in a common horizontal plane, until the pile yarn with the selected color comes to lie just above the pick line of the gripper jaws. With GB 1 150 822 the selection occurs by means of a paper card as data carrier. This device has a card switching device and an pressing device which pushed a pin corresponding to the color to be selected out of the pile yarn carriers. Through a sliding mechanism the pins are brought into a line through which the pile yarn carriers will slide and therefore the selected color is brought to the line of the gripper jaws. Each color to be selected has a specific position on the card. A perforation in that specific position in the paper card signifies the corresponding color is not selected and no perforation signifies that the corresponding color is selected. The production of a such a perforated paper card is very time-consuming and expensive and the device is rather laborious because a rotating movement and a vertical pressing movement of the prismatic cylinder have to be provided.